The largest terrestrial predator on Earth is losing the ground under its feet. Polar bears used to dominate the expanse and loneliness of the Arctic, which can seem unaffected by human presence so far. However, appearances deceive. The polar bear is now a symbol of the many species whose survival is at risk because of the effects of climate change and pollution.

The antics of Knut the polar bear cub in the Berlin Zoo touched the hearts of the German public and won him fans all over the world. The polar bear might look cute and cuddly, making it a perfect icon for Coca-Cola and many other organizations that wish to use its iconic recognition value to promote their cause or product. It is, in fact, a ferocious predator that spends much of each year on the sea ice hunting and, in the process, covers distances of up to 620 miles (1,000 kilometers). But the polar bear is also a vulnerable species listed on the International Union for Conservation of Nature's (IUCN) Red List — one that requires constant attention and sound conservation management if humanity is to ensure the polar bear's existence for future generations.

There have long been concerted, international efforts to conserve the polar bear, and the Polar Bear Agreement meeting in Moscow in December 2013 celebrated 40 years of collaboration among the five nations where polar bears exist — namely Canada, Greenland (an autonomous community that is part of Denmark), Norway, the Russian Federation and the United States. The meeting attendees agreed on a declaration promising to beef up the monitoring of these animals and the assessment of their status, and to commit to working toward developing a polar bear action plan for the next meeting of these countries in two years' time.

Nevertheless, these countries admitted in 2009 that climate change was the main threat that needed to be tackled. Early indications from that time were that the individual conservation efforts of the five countries were beginning to bear fruit, with most polar-bear populations at least stable — with a total of 20,000 to 25,000 individuals in the wild. But all of these hard-won advances could easily be lost if Arctic ice continues to diminish.

The Convention on Migratory Species (CMS) and its Scientific Council have been examining the effects of climate change on migration for years and, in 2011, passed an unequivocal resolution — "Migratory Species Conservation in the Light of Climate Change" — identifying the polar bear as one of the species most threatened by climate change. The resolution requested that the parties consider whether the polar bear and other similarly vulnerable migratory species should be listed under the protection of the CMS Appendices.

Climate change, which is leading to reduced ice cover and the thawing of permafrost, is not the only factor having detrimental effects on polar bears. Increased economic activities, such as oil and gas exploration and exploitation, and shipping, are also taking their toll. As apex predators, polar bears are vulnerable to environmental pollutants, and post-mortems have shown dangerous levels of mercury and other toxins in the animals. These pollutants even affect newborn cubs, which ingest the poisons in their mothers' milk. Governments have to strike a fine balance: How are they to protect a fragile environment and forsake economic opportunities while exploiting much needed natural resources and creating jobs and wealth? The choices made often make the prospects for the polar bears bleaker, with fewer places for them to hunt and build dens in which to raise their young.

The CMS is a global treaty whose parties have committed to working together to conserve the hundreds of species listed on its appendices. These range from the blue whale to the monarch butterfly to gorillas, whose territories straddle the borders of the Democratic Republic of the Congo, Rwanda and Uganda, and the arctic tern, which covers hundreds of thousands of kilometers in a lifetime in its pole-to-pole migrations. As a worldwide convention, CMS has the breadth to deal with species such as the polar bear in the context of climate change, adding a global perspective to conservation policies. The convention is used to dealing with multiple threats — such as pollution, climate change and environmental degradation — and it is recognized as the Convention on Biological Diversity's lead partner on the conservation and sustainable use of migratory species. It has a catalog of more than 30 years' worth of wide-ranging policies and a track record of fostering international cooperation.

At the International Forum on the Conservation of Polar Bears — which was held in December and attracted high-level participation, including from Russian Environment Minister Sergei Donskoi and his Canadian counterpart, Leona Aglukkaq — delegates were confronted with a disturbing prediction: The polar-bear population could fall by as much as two-thirds by 2050. Nations need to take action now, and the bears need all the friends they can get. CMS is ready to play its part if its parties agree to include the polar bear under its appendices.